(M) Week 9: Test for red cell energy and metabolic defect Flashcards
A screening test used to determine the presence of normal activity of the G-6-PD and Pyruvate kinase in the blood
Florescent spot test
this deficiency causes acute hemolytic anemia after the patient is exposed to an oxidizing substance produced from the metabolized administered drugs
G-6-PD
drugs such as certain antibiotics and anti-malarial drugs form peroxide which oxidizes the _______________ in the absence of G-6PD enzyme forming _______________-
hemoglobin
heinz bodies
match the principle to the test
approximately 1 ml drop of anticoagulated whole blood using either EDTA, Heparin or ACD anticoagulant, is placed to a special filter paper which is then mixed with a drop of a test reagent containing glucose-6-phosphate and NADP
a. Florescent spot test
b. glutathione reduction test
c. acute hemolysis test
d. ascorbate cyanide test
a
if there’s enough level of G-6-PD a chemical reaction will occur which converts the NADP to
reduced NADP or NADPH
there’s fluorescence if NADPH is absent/present
present
major enzyme in the EMP pathway, responsible for the production of enough ATP
Pyruvate kinase
Deficiency of this enzyme may cause the instability of the red cell
membrane due to the insufficient production of energy that eventually leads to hemolytic anemia.
pyruvate kinase
match the principle to the test:
A drop of blood is placed in a filter paper and mixed with a test reagent
containing phosphoenol pyruvate, ADP, and reduced nicotinamide-adenine dinucleotide or NAD
a. Florescent spot test
b. glutathione reduction test
c. acute hemolysis test
d. ascorbate cyanide test
a
If there is enough pyruvate kinase in the blood a chemical reaction will occur that leads to the conversion
of NADH to___________
NAD
the presence of NAD (hinders/promotes) fluorescence
hinders
what is the positive result for pyruvate kinase enzyme
no fluorescence
What are the factors that may cause a false normal for pyruvate kinase and G-6PD tests?
high WBC (>20,000/ul)
high platelet count
what are the factors that may cause a false normal result for G-6PD testing
high levels of reticulocyte
what may cause for pyruvate kinase test to have a false positive result
plasma
what effect does hemoglobin have on fluorescence
quenching
if the hematocrit of the person is more than 50% it is recommended that _________ of the required amount of specimen is used
only half
if the hematocrit is__________ the amount of specimen should be doubled.
less than 20%
which test has the same principle as the fluorescent spot test
glutathione reduction test
If the blood is containing normal levels of Glutathione reductase (GSSG-R) the NADPH will be converted to
NADP
if there’s a normal level of glutathione in the blood, the sample will fluoresce for ___________–
20 minutes
in glutathione reductase deficiency the fluorescence will persist and continue for _____________
more than one hour
This test is used to screen the two most common red cell enzymopathy and these are the G-6-
PD deficiency and pyruvate kinase deficiency.
auto hemolysis test
G6PD/PK DEFICIENCY
what is the test for this principle?
Blood specimen is subjected into warm temperature
ranging from 37OC to 40OC for 48 hours
autohemolysis test
autohemolysis test
if the blood is deficient with either of the G6PD or pyruvate kinase, the red cells will be
lysed => reddish plasma
what is used to correct the occurences of hemolysis in autohemolysis test
glucose reagent or ATP reagent
If the hemolysis is corrected by adding glucose reagent but not with ATP
reagent, then the patient has
G-6-PD deficiency ( Auto hemolysis type I,)
if the hemolysis is not corrected by the glucose reagent but corrected by the ATP reagent, then the patient has
pyruvate kinase deficiency (s Auto hemolysis type II,)
If both the glucose and ATP reagent corrected the hemolysis, then the patient is suffering from
hereditary spherocytosis (s Auto hemolysis type III)
Test used to diagnose an autoimmune disorder known as Paroxysmal
Cold hemoglobinuria (PCH)
Donath-Landsteiner test
a condition where a person produces an anti-P autoantibody
PCH
infections that trigger the production of anti-P autoantibody
syphilis
auto anti-P usually binds with red cell membrane at ____________ and triggers red cell hemolysis at ____________ by activating the complement system
cold temp
37 deg c
Which test has this principle?
uses two separate tubes filled with whole blood. One of the tubes is
incubated at 37OC for 60 minutes which is the control tube and the other tube is incubated first at 0-4
OC for 30 minutes then later at 37OC for 60 minutes
Donath-Landsteiner test
positive result for Donald-Landsteiner test
incubated - hemolysis (at 37 degree)
no hemolysis on control tube
negative result for Donald-Landsteiner test
no hemolysis on both tubes
What is the interpretation if both tubes showed bemolysis in the Donald-Landsteiner test
negative for PCH
test is used to determine the in vivo attachment of an
auto or allo antibody and complement fragments on red cell membrane
Direct Antihuman Globulin Test (DAT)
in vivo attachment of an auto or allo antibody and complement fragments on red cell membrane occurs on the following conditions:
autoimmune hemolytic anemia
hemolytic transfusion reactions
hemolytic disease of the newborn
PCH
What reagent is used by the direct antihuman globulin test
Antihuman globulin (AHG) or Coomb’s reagent
